The spine is critical in human physiology for mobility, support, and balance. The spine protects the nerves of the spinal cord, which convey commands from the brain to the rest of the body, and convey sensory information from the nerves below the neck to the brain. Even minor spinal injuries can be debilitating to the patient, and major spinal injuries can be catastrophic. The loss of the ability to bear weight or permit flexibility can immobilize the patient. Even in less severe cases, small irregularities in the spine can put pressure on the nerves connected to the spinal cord, causing devastating pain and loss of coordination.
Surgical procedures on the spine often include the immobilization of two or more vertebrae. Immobilizing the vertebrae may be accomplished in many ways (e.g. fixation plates and pedicle screw systems). One of the most common methods for achieving the desired immobilization is through the application of bone anchors (most often introduced into the pedicles associated with the respective vertebrae to be fixed) that are then connected by rigid rods locked to each pedicle screw. These pedicle screw systems are very effective. However, vertebrae of pediatric patients can be small, making the use of pedicle screws challenging, and the vertebrae of trauma patients, or patients having decreased vertebrae strength, may not have sufficient bone structure with which to use pedicle screw systems. Therefore, a need continues to exist for new bone fixation devices that can be used as alternatives to pedicle screws.